Thread protector for casing



April 1963 c. HICKMAN ET AL 3,087,512

THREAD PROTECTOR FOR CASING Filed May 17, 1961 2 Sheets-Sheet 1 Char/es F. Hickman Edward P. Gopenhaver uvmvroxs c. F. HICKMAN ETAL 3,087,512 THREAD PROTECTOR FOR CASING April 30, 1963 2 Sheets-Sheet 2 Filed May 17, 1961 Edward P. Copenhaver INVENTORS BY MW Em m K m H M w 0 m Fig.4

United States Patent '0 3,087,512 THREAD PROTECTOR FOR CASING Charles F. Hickman, Alice, and Edward P. Copenhaver, San Antonio, Tex.; said Hickman assignor to said 'Copenhaver Substituted for abandoned application Ser. No. 537,644, Sept. 30, 1955. This application May 17, 1961, Ser.

11 Claims. Cl. 138-96) This invention comprises a novel and useful thread protector for casings and more specifically relates to a protective housing assembly adapted to embrace and protect the threaded extremities of well casings and the like and is particularly characterized by an improved and highly advantageous mechanism for quickly releasably securing the protective device to a casing and for compactly housing the same within the interior of a casing.

This application is a substitute for abandoned application, Serial No. 537,644, filed September 30, 1955.

The principal object .of this invention is to provide an inexpensive and easily applied and removed device for effectively protecting the threaded extremities of well casings and the like.

Specific objects of the invention are to provide a protective device in conformity with the preceding objects wherein an improved and compact mechanism for operatingthe means for releasably attaching the device to a casing is provided, wherein all of the moving parts of the device are adapted to be disposed entirely within the casing whose threads are protected by this device, and wherein only the operating handle for actuating the attaching mechanism is accessible on the exterior of the casing and wherein the operating handle is recessably housed within the device.

These, together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a perspective view of a portion of the end of a well casing or similar article and showing the manner in which the thread protecting device of this invention has been applied;

FIGURE 2 is a vertical, transverse enlarged sectional view taken substantially upon a plane indicated by the section line 2-2 of FIGURE 1 and showing the manner in which the locking jaws of the device are operatively engaged with the'interior surface of the casing when the protective device is applied thereto;

FIGURE 3 is a perspective view of a portion of the protective device with the locking jaws and the actuating mechanism of the same being removed therefrom;

FIGURE 4 is a vertical, sectional view taken upon a larger scale substantially upon the plane indicated by the broken section line 44 of FIGURE 2 and showing the position of the parts when the device is engaged in protective relation upon a casing about the threaded extremity of the same;

FIGURE 5 is afragmentary, horizontal sectional detail taken substantially upon the plane indicated by section line 5-5 of FIGURE 4 and in particular illustrating the manner in which the locking jaws of the device are mounted for and are limited to radial movement relative to the casing with which the jaws are adapted to cooperate;

FIGURE 6 is a horizontal, sectional view taken substantially upon the plane indicated by the broken section line 6-6 of FIGURE 4 and illustrating in particular one 'of-the jaw actuatinglinks andsthetmanner in which the for convenience in the drawings.

3,087,512 Patented Apr. 30, 1963 "ice same is pivoted to the jaw and to a carriage for actuating one of the jaws; and

FIGURE 7 is a perspective view of a carriage to which the actuating links of the plurality of jaws are connected for simultaneous operation.

The general purpose of this invention is to provide a protective device which can be easily applied to or removed from the threaded extremities of well casings or other pipes in order to protect the threads of the latter when a plurality of such casings or pipes are stored or stacked in readiness for or during well drilling or other operations. It is a prime requisite for such devices that they shall be of durable construction, shall be effective for protecting against damaging the threads of expensive well casings, and that they shall be easily applied to or removed from such casings.

In accordance with these purposes, the accompanying drawings show the preferred embodiment of protective device in conformity with the principles of this invention, and which device is adapted to embrace and pro tect the threaded extremity 10 of a well casing 12. It will be seen that the protective device designated generally by the numeral 14 is adapted to receive and embracingly protect the threaded extremity 10, while substantially all of the operative structure of the device will be housed within the end of the casing as will be clearly apparent from FIGURES 1 and 4.

The protector 14 comprises a body 16 which may conveniently consist of a circular flat plate which is of sufficient size to be loosely received within the interior of a well casing 12 with which the device is intended to be used. About its periphery, as shown best in FIG- URE 4, the body 116 has a depending .or laterally positioned annular shield or guard 18. The latter member consists ofa pair of radially spaced concentric inner and outer cylindrical flanges or walls 20 and 22 respectively, .the former being integral with the rim of the body 16, while the walls 20 and 22 are connected to each other at their outer ends by an annular web 24. The combined walls and web thus define a cylindrical or annular chamber '26 therebetween, see FIGURE 3, which chamber is adapted to loosely receive the threaded extremity 10 of the casing 12.

.As so far described, and as shown in FIGURES 1 and 4, it will be evident that when the threaded extremity 10 of the casing 12 is disposed in theannular chamber 26 of the guard, the .body 1'6 will be disposed well within the interior .of the casing, and only the annular web portion of the guard 18 will-extend beyond the end of attaching the device to a well casinng and the means for operating the attaching means are all compactly positioned Within the well casing and protected against possible damage by such positioning.

Rising f rom what may be termed the inner surface of the body .16, that is from the surface which is on the opposite side of the body from the web 24, are a plurality of supports 28, three such supports being indicated These supports, as illustrated, may be in the form of upstanding lugs or plates, disposed substantially radially of the body 1;; and adjacent the periphery of the latter. Each support is provided with a slot 3i) which is substantially parallel to the body 1 6 and di po ed sub t n ia ly r di y of t cylindrical surface of the casing 12 with which the device is adapted to be used.

Mov-ably mounted upon the supports 28 and coupled thereto by pin and slot connections are a plurality of ijaws 32, there being provided one jaw for each support,

andeach jaw consisting of a body having a convex outer surface provided with a plurality of circumferentially extending teeth or other gripping means 34 adapted to engage the interior concave surface of the well casing 12. As suggested in FIGURE 4 and as clearly shown in FIGURE 5, each of the jaws 32 is provided at its lower end with a slot 36 which is adapted to loosely embrace the :siotted extremity of the support 23. A pin 38 is tea-fried by each jaw 32 and extends across the slot 36 'ihereof and is slidably received within the slot 30 of the support. Thus, each jaw is secured to its corresponding support 28 by means of the pin 38 whereby the movement of the jaw is limited to a pivotal movement about its pin 38 and to a radial sliding movement afforded by movement of the pin in the slot 30. Thus, each jaw is limited to movement radially towards and from the cylindrical inner surface of the well casing 12 or to a slight pivotal movement about the pin 38 as will be more apparent hereinafter.

Mechanism is provided to facilitate actuation of the jaws to effect their locking engagement with or their release from the inner surface of the casing 12. For this purpose there is provided a toggle assembly comprising a screw or bolt 40 which is threaded through the body 16 and through a centrally disposed internally threaded tubular boss 42 disposed on the opposite side of this body from the supports 28. The bolt 40 is conveniently provided with a handle 44 whereby the bolt may be {manipulated from within the cylindrical chamber formed by the inner cylindrical wall 20 and from the interior of the end of the well casing, as will be readily understood from FIGURES 1 and 4,

The bolt is provided with an annular shouldered portion or bearing surface 46 and terminates in a diametrically reduced axial extension 48. A carriage 50, see also FIGURE 7, is provided with a central aperture 52 Whereby the carriage is loosely rotatably carried by the axial extension 48 and rests upon the annular shoulder 46, being prevented from or limited as to axial movement upon the axial extension as by a retainer pin 54 and a retainer washer 56. It will thus be apparent that as the bolt 40 is rotated, the carriage 50 will be moved axially of the body 16 and of the well easing 12.

A plurality of bifurcated or pairs of parallel standards 60 apertured as at 62 are carried in upstanding relation by the carriage, there being provided one of said bifurcated standard or pair of standards for each of the supports and ,ja'ws previously mentioned. A connecting link n4 is provided connecting each standard 60 to one of the aws 32. For this purpose, the link may be pivoted as at 66 in the bifurcated standards. The other end f each link is pivoted as by a pivot pin 68 to one of the aws 3-2, the link and pin extending into a recess or slot f7 which is formed in the jaw. This connection of the link to the jaw and to the standard carried by the carriage is shown in FIGURES 2, 4 and 6.

It will be observed that the links constitute a mechanism whereby when the bolt 40 is moved axially of the tubular boss 42, the jaws 30 will be urged radially towards or from the casing 12, such movement being permitted by the movement of the pin 38 in the slot 30, and by the inclination of the links between their pivot connections 66 and 68. It should be further noted that the entire securing mechanism other than the handle 4-4 of the screw 40 is disposed inwardly of the body 16 whereby the same is protected upon the interior of the well casing 12 from access from the end of the casing by means of the plate 16. This insures that the mechanism will be protected against the detrimental effects of dirt and the like. The actuating handle 44- is itself protectively recessed and housed with the cylindrical chamber lying within the cylindrical inner Wall 20 of the guard 18.

It will be further noted that the pivot connections 68, 66 of the links 64 are spaced axially as well as radially of each other while the ends of the,- links are received and guided against twisting about their longitudinal axes in the slots 70 of the jaws 32 and in the slots in the bifurcated standards 59. This spacing provides a mechanical advantage in converting the upward thrust of the bolt 40 into a radial thrust on the jaws. Moreover, the guiding action of the links 64 in the slots 70 and of the supports 28 in the slots 36 maintain the jaws each in a single plane extending axially and radially of the device thereby reducing lost motion and tendency to cock or bind in its p.votst From the foregoing, the construction and operation of the device will be readily understood and further explanation is believed to be unnecessary. However, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the appended claims.

What is claimed as new is as follows:

1. A thread protector for the exteriorly threaded end of a casing, said protector comprising a body, a shield on said body adapted to loosely surround and protect the exterior thread of a casing, supports on said body, jaws adapted to engage the interior surface of a casing, guide and pivot means securing said jaws to said supports for limiting the jaws to radial movement on the body, and actuating means operatively connected to said body and to said jaws for causing movement of the latter toward and from a casing, said actuating means comprising a carriage disposed between said jaws, means mounting said carriage for adjustable movement toward and from said body and axially thereof, links pivoted to said carriage and to said jaws.

2. A thread protector for the exteriorly threaded end of a casing, said protector comprising a body, a shield on said body adapted to loosely surround and protect the exterior thread of a casing, supports on said body, jaws adapted to engage the interior surface of a casing, guide and pivot means securing said jaws to said supports for limiting the jaws to radial movement on the body, and actuating means operatively connected to said body and to said jaws for causing movement of the latter toward and from a casing, said actuating means comprising a carriage disposed between said jaws, means mounting said carriage for adjustable movement toward and from said body and axially thereof, links pivoted to said carriage and to said jaws, said body having a threaded boss upon the opposite side thereof from said supports, an adjusting screw threaded in said boss and secured to said carriage.

3. A thread protector for the exteriorly threaded end of a casing, said protector comprising a body, a shield on said body adapted to loosely surround and protect the exterior thread of a casing, supports on said body, jaws adapted to engage the interior surface of a casing, guide and pivot means securing said jaws to said supports for limiting the jaws to radial movement on the body, and actuating means operatively connected to said body and to said jaws for causing movement of the latter toward and from a casing, said actuating means comprising a carriage disposed between said jaws, means mounting said carriage for adjustable movement toward and from said body and axially thereof, links pivoted to said carriage and to said jaws, said carriage having a plurality of standards, said jaws having recesses therein, said links extending into said recesses and being pivoted terminally to said jaws and standards.

4. A thread protector for the exteriorly threaded end of a casing, said protector comprising a body, a shield on said body adapted to loosely surround and protect the exterior thread of a casing, jaws on the body engageable in the casing for securing the shield thereon, and means for actuating the jaws, said means including a toggle assembly comprising a screw threadedly mounted on the body, a carriage swivelly mounted on the screw, and means operatively connecting said carriage to the jaws for engaging said jaws with an disengaging said jaws from the casing.

5. The combination of claim 4, wherein the last-named means includes links pivotally connected to the carriage and the jaws.

6. The combination of claim 5, wherein said jaws have slots therein pivotally receiving the outer end portions of the links for laterally stabilizing said jaws thereon.

7. The combination of claim 4, together with means anchoring the jaws to the body for radial sliding and swinging movement.

8. The combination of claim 7, wherein the last-named means comprises pin and slot connecting devices between the jaws and the body.

9. A thread protector for the exteriorly threaded end of a casing, said protector comprising a body insertable in a casing, a shield on said body adapted to loosely surround and protect the exterior thread of the casing, radial lugs on the body inserta'ble therewith in the casing, a plurality of toothed jaws insertable in the casing, pin and slot connections coupling said jaws to the lugs for radial sliding and swinging movement in the casing, and means for engaging said jaws with the casing for securing the shield on the casing, said means comprising a toggle assembly including a screw threaded through the body,- said screw comprising a reduced end portion providing a shoulder, a carriage journaled on said reduced end portion and resting on the shoulder, means retaining the carriage on the reduced end portion of said screw, and means operatively connecting the carriage to the jaws.

10. The combination of claim 9, wherein the lastnarned means comprises bifurcated standards on the carriage, and links having one end portion pivotally secured in the standards and their other end portions pivotally connected to the jaws.

11. The combination of claim 10, said jaws having slots therein receiving said other end portions of said links for laterally stabilizing the jaws thereon.

References Cited in the file of this patent UNITED STATES PATENTS 2,196,454 Kahn et al. Apr. 9, 1940 2,238,642 Hicks Apr. 15, 1941 2,414,441 Braucher Jan. 21, 1947 2,547,992 Baker Apr. 10, 1951 2,670,799 Dobbs Mar. 2, 1954 FOREIGN PATENTS 1,237,248 France June 20, 1960 

4. A THREAD PROTECTOR FOR THE EXTERIORLY THREADED END OF A CASING, SAID PROTECTOR COMPRISING A BODY, A SHIELD ON SAID BODY ADAPTED TO LOOSELY SURROUND AND PROTECT THE EXTERIOR THREAD OF A CASING, JAWS ON THE BODY ENGAGEABLE IN THE CASING FOR SECURING THE SHIELD THEREON, AND MEANS FOR ACTUATING THE JAWS, SAID MEANS INCLUDING A TOGGLE ASSEMBLY COMPRISING A SCREW THREADEDLY MOUNTED ON THE BODY, A CARRIAGE SWIVELLY MOUNTED ON THE SCREW, AND MEANS OPERATIVELY CONNECTING SAID CARRIAGE TO THE JAWS FOR ENGAGING SAID JAWS WITH AN DISENGAGING SAID JAWS FROM THE CASING. 